Replace the current libxl driver code for managing port
reservations with the new virPortAllocator APIs.

Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Based on a patch originally authored by Daniel De Graaf

  http://lists.xen.org/archives/html/xen-devel/2012-05/msg00565.html

This patch converts the Xen libxl driver to support only Xen >= 4.2.
Support for Xen 4.1 libxl is dropped since that version of libxl is
designated 'technology preview' only and is incompatible with Xen 4.2
libxl.  Additionally, the default toolstack in Xen 4.1 is still xend,
for which libvirt has a stable, functional driver.

Currently to deal with auto-shutdown libvirtd must periodically
poll all stateful drivers. Thus sucks because it requires
acquiring both the driver lock and locks on every single virtual
machine. Instead pass in a "inhibit" callback to virStateInitialize
which drivers can invoke whenever they want to inhibit shutdown
due to existance of active VMs.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c

Update the libxl driver to use virReportError instead of
the libxlError custom macro
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

v3:
* initialize xml pointer to avoid segfault
* throw error message if domain is paused as
  libxenlight itself will pause it

v2:
* header is now padded and has a version field
* the correct restore function from libxl is used
* only create the restore event once in libxlVmStart

This patch fixes the population of the
libxenlight data structures. Now the devices
should be removed correctly from the xenstore
if they are detached.

Create 3 new function refactored from previous list ones and
exports them internally to the driver

* src/libxl/libxl_conf.c src/libxl/libxl_conf.h: create libxlMakeDisk,
  libxlMakeNic libxlMakeVfb out of the exsting static List functions
  and exports them

And from all related macros and functions.

* src/libxl/libxl_conf.[ch] src/libxl/libxl_driver.[ch]: add authors
  after the licence template

* src/libxl/libxl_conf.h: add the necessary fields to the driver
  private structure
* src/libxl/libxl_driver.c: add lifecycle event support and entry
  points for event(de)register(any)

Add a new xen driver based on libxenlight [1], which is the primary
toolstack starting with Xen 4.1.0.  The driver is stateful and runs
privileged only.

Like the existing xen-unified driver, the libxenlight driver is
accessed with xen:// URI.  Driver selection is based on the status
of xend.  If xend is running, the libxenlight driver will not load
and xen:// connections are handled by xen-unified.  If xend is not
running *and* the libxenlight driver is available, xen://
connections are deferred to the libxenlight driver.

V6:
 - Address several code style issues noted by Daniel Veillard
 - Make drive work with xen:/// URI
 - Hold domain object reference while domain is injected in
   libvirt event loop.  Race found and fixed by Markus Groß.

V5:
 - Ensure events are unregistered when domain private data
   is destroyed.  Discovered and fixed by Markus Groß.

V4:
 - Handle restart of libvirtd, reconnecting to previously
   started domains
 - Rebased to current master
 - Tested against Xen 4.1 RC7-pre (c/s 22961:c5d121fd35c0)

V3:
  - Reserve vnc port within driver when autoport=yes

V2:
  - Update to Xen 4.1 RC6-pre (c/s 22940:5a4710640f81)
  - Rebased to current master
  - Plug memory leaks found by Stefano Stabellini and valgrind
  - Handle SHUTDOWN_crash domain death event

[1] http://lists.xensource.com/archives/html/xen-devel/2009-11/msg00436.html